Sewing-machine



R. K. HO HMANN. SEWING'MACHINEf APPLICATION FILED FEB. 26, 1916.

1,343,823. Patented June 15, 1920.

7SHEETSSHEET l.

R. K. HOHMANN.

SEWING MACHINE.

APPLICATION FILED FEB. 26, 1916.

7 SHEETSLTSHEET 2.

Patented June 15, 1920.

R. K. HOHMANN. SEWING MACHINE.

APFLICATION FILED 353 26, 1913.

J SHEETS-SHEET 3.

v WKMM MyW 3333' v R. K. HOHMANN.

SEWlNG MACHINE.

APPLICATION FILED Fmz's, me.

1 43,823 Patented June 15, 1920.

R. K. HOHMANN. SEWING MACHINE.

APPLICATION FILED FEB. 26, 1916.

- Patented June 1551920.

7 SHEETSSHEET 6. f Jfli R. K. HOHMANN.

SEWING MACHINE. APPLICATION FILED nzm'zs, 1915.

Patented J um) 15, 1920.

I YSHHETS-SHEET 7.

- of operations, .the slow BICITABD K. HOHMANN, OF SIOUX CITY, IOWA.

SEWING-MACHINE.

Specification of Letters Patent. Patnted June 15', 1920 Application filed February 26, 1916. Serial No. 80,673.

To all whom it may concern Be it known that I, RICHARD K. HOHMANN, a citizen of the United States, and resident of Sioux City, \Voodbury county, State of Iowa. have invented certain new and useful I m provements in Sewing-Machines, of which thefollowing is a specification.

This invention relates to sewing machines and particularly to machines of the rotary type adapted to operate at extremely high speeds. It is one of the objects of the invention to eliminate the usual differential crank drive which produces a fastand slow movement of the shuttle during each cycle movement being for the purpose of giving to the take up time to draw up the needle loop. A further object of the invention is to provide a machine having a rotary stitch forming member which operates at a uniform speed so as to have the minimum wear on the parts and to permit of operation at a maximum speed.

.further object of the invention is to provide a rotary stitch forming member whiohacts as its own take-up and thereby avoids draw ing the needle loop back and forth through the needle, thus eliminating the wear on the thread incident to the present machines and permitting the use of an unusually large bobbin and cooperating with the other features to permit of extremely high speed operation. The use of a large bobbin makes it necessary to form a large loop in the thread and if this loop is drawn back and forth through the needle eye the wear and friction become so excessive as to result in frequent breaking of the thread and consequent stoppage of the operation of the machine.

A further object of the invention is to provide a machine embodying the features above referred to and also capable of makin either the lock or chain stitch. I

With the foregoing and other objects'in view, as will appear from the following detailed description, the invention may be embodied in various forms of mechanism some of which are illustrated in the accompanying drawings.

In the drawings:

Figure 1 is a skeleton side elevation of a sewing machine head of the rotary shuttle Fig. 2 is an end elevation of the same; Fig. 3 is a bottom plan view; Fig. 4 is a longitudinal section through the shuttle mechanism;

- needle loop.

Fig. 5 is a side elevationof a modified form of shuttle;

Fig. 6 is an edge view of the same;

Fig. 7 is a transverse section on the line 7-7 of Fig. 5;

Figs. 8 t0'13 are side elevations 'of the shuttle in the various positions of forming a stitch;

Fig. 14 is Fig. 2;

Fig. 15 is an end elevation of the stitch forming mechanism of a machine of the revolving hook type embodying the invention;

Fig. 16 is an elevation pf the shuttle mechanism of Fig. 15 but shown in a different position to illustrate the formation of the a section on the line 11-1 1 of stitch Fig. 17 is a section substantially on the line 17-17 of Fig. 16',

Fig. 18 is an elevation of the shuttle shown in Figs. 8 to 13 but without the bobbin. thread and in combination with means for forming the chain stitch; and

Fig. 19 is a plan view of the mechanism shown in Fig. 18.

Referring to the drawings it will be seen that the sewing machines illustrated are im provements in the type of machine illustrated in the Richards Patent No. 669,827, in which patent the revolving shuttle is provided with three hooks each of which takes the needle thread once for every two revolutions the loop formed by one of the shuttle hooks being drawn up by the second following hook which is angularly spaced 2&0 therefrom. I have found from actual experience that it is commercially impracticable to have a multiplicity of hooks upon a shuttle because the variations and inaccuracies incident to the commercial production of machines result in the hooks being slightly out of alinement so that stitches are occasionally omitted due to the failure of a particular hook to catch the needle thread when it should. I have overcome this difiiculty by providing a machine in which the shuttle or revolving part carrying the hook makes one complete revolution for each reciprocation of the needle and therefore carries but a single hook and the slight variations in'the different shuttles as manufactured commercially are of no consequencebecause it is possible to adjust the shuttle in an axial direction so that its hook will always take the This is not possible with a shuttle, having a multiplicity of hooks, because, as above stated, the hooks are not in alinement and in adjusting the shuttle to suit one hook another or others will be thrown out of adjustment.

Referring particularly to Figs. 1 to 14 it will be seen that the machine illustrated comprises the usual base or work support 20 on which is arranged an arm 21. A main drive shaft is supported in: suitable hearings in the arm 21 and carries at .its outer end a driving pulley or wheel 23. needle bar 24 is slidably mounted in the enlarged endof the arm 21 in the usual manner andis operatively connected with the shaft 22 bynieans of the pitman 25 or any other suitable mechanism; many forms which are well known to those skilled in this art. The usual presser-foot 26 is arranged on the lower end of the rod 27 and is yieldingly held in its different positions by means of the spring 28. A. cam 29 mounted on a pivot 30 and cooperating with the arm iil on the rod 27' is provided for the purpose of raising orlowering thefoot 26 as desired, the cam being conveniently operated by means of the hand lever 32. This part of the mechanism may also be of any well known and suitable form.

The arm 21 has the usual spool spindle 83 and the thread a extendsfrom the spool around a guide 34 and through a tension device whence it passes under a hook 36. From the hook36 the thread passes through a guide 37 to an arm 38 which is carried by the needle bar 241 From the arm 38tl1e thread passes under a leaf spring tension device 39 and thence through the eye of the needle 40 on the lower end of the needle bar. The usual cloth feed 41 is provided under the pressure foot 26 and may be actuated by any well known or preferred mechanism. and in Fig. 2 the eccentric rods 42 and 43, actuated by suitable eccentrics on the shaft 22 are provided for this purpose. A shaft 44 is journaled in the bearings 45 and 46 on the under side of the support 20 and carries at one end a disk 47 having pins 48 and 49 projecting from diametrically opposite points thereon. The other end of the shaft 44 carries a gear wheel 50, preferably a spiral gear. which meshes with and is driven by a corresponding gear 51 on the vertical shaft 52, the upper end of which carries a similar gear 53,which meshes with the gear 54 on the main shaft 22. .Thegears 51, 52, 53 and 54 are so proportioned that the shaft 44 rotates at exactly the same speed as the shaft 22 or "in synchronism with the latter and in synchronism with the reciprocations of the needle bar 24. A shuttle housing or' frame 55 is secured on the bracket 56 which projects from the bearing member 45. A shuttle 57 is rotatably mounted in the frame and supported by the latter in an in- .holder- 65 .for

clined position relatively to the disk 47 as clearly illustrated in Fig. 4. The shuttle 57 has a peripheral flange 58 which runs in a groove in the frame and thus holds the shuttle in position. The shuttle is provided with openings 59 and 60 arranged to receive the pins 48 and 49 respectively so that the shuttle may be driven from the shaft 44.

In forming a stitch with this mechanism it is necessary for the needle thread to be carried around the shuttle or to have the shuttle, in effect, passed through the loop in the needle'thread, and-in order to permit this the shuttle is arranged at an incline relatively to the disk 47 and when the pins 48 and 49 are in the position shown inFig. 4 only the pin 49 is connected-with the shuttle, the pin 48 being spaced from the shuttle to permit the'thread loop to he passed beween the end of the pin and the shuttle. As the shaft 44 rotates from the position shown in Fig. 4 the pin 48 will an essential part of the present invention.

In Figs. 5, 6 and 7 there is illustrated a modification of the shuttle structure shown in Fig. 4 and instead of a single flange 58 on the shuttle a groove 61 is provided in which a tongue 62 on the frame projects, this construction being merely a reversal of that shown in Fig. 4. The shuttle 'shown in Figs. 5, 6 and 7 is otherwise the same'as that illustrated in Fig. 4.

, At the center of the shuttle a post 63 is provided for the bobbin 64 and a holder 63 for the shuttle extends over the outer end thereof and is secured in position on the post 63 by means of the latch 66 which engages the groove 67 in the post. The bobbin holder 65 has an arm 68 which projects into a notch 69 in a stationary plate 70 for the purpose of. securing the bobbin holder against rotation. The thread (2 extends and thence upwardly,through the opening 69 in the needle plate 70, suitable tension means, (not shown) being provided on the giving the proper tension to the thread I).

Referring more particularly to Figs. 8 to 13 the details of construction and operation of the shuttle will be made apparent. It will be seen that the shuttle is provided with a single book .71 and a circumferential groove 72 (see also Figs. 6 and 7 )v for the needle thread. The shuttle rotates in the direction of the arrows in Figs. -8 to 13 and in the position of the shuttle in Fig. 8 the loop in the needle thread a extends around theshuttle in-an axial direction from the hook 71 so that one side of the loop is arranged across the back of the shuttle and the other side is laid in the groove-72. The

' needle is descending and provides the" necessary slack in-the thread to permitthe 'shuttle to continue its rotation to the position shown in Fig. 9, where the needle. is about to puncture the cloth 0. In this position all of the needle loop with the exception of the small portion 73 is arranged on the front of the shuttle and as the-latter rotates from this position the eccentrically arranged portion'74r of the thread groove takes up the slack in the loop which resultsfrom the portion 73 jumping over to the front of the shuttle to the position shown in Fig. 10.

In the latter position the bobbin thread 6 I extends up to the cloth and the needle is movement. This position of the different threads is maintained until the hook 71, enters the loop in the needle thread which is formed when the needle starts upward, this occurring just before the hook reaches the position indicated in Fig. 11. -.The portion 7 5 of the shuttle has no groove for the threadloop and as a consequence the rotationof the shuttle; from the position shown in Fig. 11 to the position shown in Fig. 12 results in casting the loop from the shuttle so that it incloses the bobbin thread I). Further rotation of the shuttle from the position shown in,Fig.,12 results in the hook forming the new loop 7 6 by drawing the cast-off loop through the cloth. In Fig. 13 the cast-01f 1 loop is indicated at 7 and as the shuttle rocommon forms of take-ups.

tates to the position shown in Fig. 8 the loop 77 is drawn into thecloth, carrying with it the thread Z2 and thus forming the being atthe same time carried to the posi. tion of the loop indicated in Fig. 8.

From the foregoing it will be evident that the hook 71 takes the needle thread and carries it around the shuttle, in effect passing the bobbinthrough the loop and then draws or takes up the slack by catching the needle thread and forming a new loop therein, the shuttle thus acts as its own take-up and it is unnecessary to draw the thread back and forth through the needle eye as in the more takes the needle thread on each revolution and therefore the needle. is reciprocated in synchronism with the rotations of the shuttle. v 8

Referring to Figs. 18 and 19 it will be seen that l have illustrated 'means whereby the mechanism above described may be employed for also forming a chain stitch, in

which case the bobbin thread is omitted.

In order to form the chain stitch with this mechanism a finger 78 is provided, this fin- The hook 71' ger being adapted'to rock on the pivot 7 9 and having rigidly connected therewith an arm 80 the outer endof which is moved to and fro by an eccentric rod 81 which is operatedzby an eccentric82'on the shaft 4.4;.

;As shown in Fig. 19 the finger 7 8 deflects producing the well known chain stitch.

' In the form of the inventionillustrated in Figs l to 1 1 aguard plate 83 is arranged infront of the shuttle and cooperates with the plate to guide the thread loop after it h ats been cast off from the shuttle.

In Figs. 15, 16 and 17 a machine of the revolving hook type embodying the invention; is illustrated and in this machine the shaft 44L carries a frame 84: on which the hook ring 85 is secured. This hook ring has a hook 86 to take the thread from the needle, and is also provided with a circumferential- .thread groove 87 and a horn 88, the latter being located in proximity to the hook 86 and pointing toward the latter. lvithin the hook ring 85 is arranged the bobbin case 89 which carries the bobbin.90,- the latter being held in the bobbin casein any preferred manner as by means of the arm 91 which is pivoted to the bobbin case at 92 and has" its free end arranged to cooperate with the bobbin stud, 93. The bobbin case has an upwardly projecting lug 94 which cooperates with a stationary bar 95 so as to be held by the latter against rotation. l

1 In Fig. 16 the parts are shown in the position which they take immediately after the hook 86 has caught the loop 96 in the needle thread, The hook ring rotates in the direction of the arrow and after making subpositions shown in Fig. 15, one side of the loop i-n-the needle thread being then in the rear of thebobbin case and the other side .of the loop being laid in the groove 87. As

the hook ring revolves from the position shown in Fig. 15the' thread will pass from behind the bobbin case and assume the position'shown in Fig. 16, in which position the hook 86 will have again caught the needle thread. As the hook ring revolves from the position shown in Fig. 16 the horn 88, being deflected forwardly fro1n.the bobbin case,

will act as a take-up for any slack in the groove 87 until the proper instant when the horn 88 will cooperate with the smooth surface 97 to cast the loop 96 off the forward side of the hook ring so that it will be drawn into the cloth by the enlargement of the new loop 96which has been taken by the hook loop 96 so as to retain the latter in the 86. The bobbin case has a hook 98 which catches the loop 96, as the hook 86 advances from the position shown in Fig. 16 and thus causes the loop to be carried around the rear thereon cooperating with the needle to takethe thread therefrom on every revolution of the member, rotary means for forming the thread taken by said hook into a loopjthe plane of'whichis substantially parallel to the plane of rotation of said member,.-means' for casting said thread loop free from said member and hook, and means for giving to said member complete revolutions in syn chronism with the reciprocations of said needle. 5 1 7' 2. In a sewing machine, the combination of 'a needle, mechanism for reciprocating the needle, 'a' rotary. member having a hook thereon cooperating with the'needle to take the thread'therefrom on every revolution of the member,.means on'said member forforming and retaining'the threadta'ken by said hook in a loop the plane ofwhich is substantially parallel to ,the plane of rotationof the member, means adapted to.cast

said threadloop free from said member,

-andmeans forgiving to said membercomplete revolutions in synchronism with the reciprocations of said needle.

3. In a'sewlng machine, the combination of a needle, mechanism for reciprocatingthe needle, a rotary member having a hook is defined in needle.

thereon and a circumferential thread groove, I

the hook cooperating with th'eneedle to'take the thread therefrom on every revolution of the member, means adapted to position the thread looptaken by the hook in said groove as said member rotates, means for casting said thread loop free from said member after the hook returns to the position where it caught the thread from the needle and means for giving to said member complete revolutions in synchronism with thereciprocations of said needle.

4. In a sewing machine, the combination of a needle mechanism for reciprocating the needle, a bobbin, a rotary member surrounding said bobbin and having a hook cooperating with the needle to take the thread there from on every revolution of the member, said member having" a, circumferential groove in which the thread loop is arranged as the member rotates and means for casting the thread loop from said groove after said hook has taken the succeeding loop from said needle and means for giving to said member complete revolutions in synchronism with the reciprocations of said 5. In a sewing machine, the combination of a needle, mechanism for reciprocating the needle, a rotary member having a hook thereon cooperating with the needle to take the thread therefrom on every revolutionof the member, a bobbin arranged withinthe member,fsaid vmember having a circumferential groove in which? the thread lgop is arranged as the member rotates," aaportion of said groove being eccentricto the axis of rotation of the member, means on the member adapted to castthe' :loop freetherefrom after said liookhas caught the next loop the" member complete revolutions in. syn chronism with'the reciproc'ations ofJsaid needle."

In testimony whereof I affix niysignature.

RICHARD K3 HQHMANN.

l fromfthe-needle and means for giving to 

